Coronary-subclavian steal: a cause of recurrent myocardial ischemia.

Coronary-subclavian steal through an internal mammary artery (IMA) graft is a rare cause of myocardial ischemia in patients who have previously undergone coronary artery bypass surgery. Two patients presented with upper extremity ischemic symptoms and recurrent angina pectoris 3 to 4 years following coronary artery bypass with in situ IMA grafts. Diagnosis of coronary-subclavian steal was confirmed by brachiocephalic arteriography, which showed tight stenosis or occlusion of the proximal subclavian artery. Coronary arteriography showed retrograde filling of the IMA with steal from the coronary circulation. Both patients were successfully treated by carotid-subclavian bypass.